Various applications require an element to be turned a specific number of times in either direction. Such applications include spiral type balance winders, window shade spring tensioners, spring tensioners (spiral type) and coil springs. For example, tilt windows are conventionally made of extruded plastic material wherein the frame is hollow. Generally, a balance is provided for the window comprised of a tubular casing secured at one end to an end of a frame member. A spring is anchored to the secured end within the casing and the spring in turn is attached to a spiral bar. In the manufacture of such windows, tension is imparted to the spring by rotating the bar a fixed number of times. The exact number of times would vary with different window constructions. It is necessary, however, in order to obtain the proper amount of tension that the exact number of rotations be made. Conventionally, the rotating of the bar is accomplished by a manually operated hand tool. In this procedure the operator must carefully count the number of rotations so that the pre-set number will be accurately obtained. This presents problems where the operator is distracted or may not be completely attentive. The responsibility of having to keep an accurate track of the number of rotations also creates a stressful working condition. It would, therefore, be desirable if some means could be achieved for rotating the bar and tensioning the spring in an automatic manner, without requiring the operator to keep track of the number of rotation.